Acquired Brain Injury
An acquired brain injury is an injury that occurs after birth and it indicates cellular damage to the brain caused by an event or disorder, such as a tumor or stroke, and unlike a traumatic brain injury, it can affect cells throughout the brain.
Causes of acquired brain injury can include, but are not limited to:
- Airway obstruction
- Near-drowning, throat swelling, choking, strangulation, crush injuries to the chest
- Electrical shock or lightning strike
- Trauma to the head and/or neck
- Traumatic brain injury with or without skull fracture, blood loss from open wounds, artery impingement from forceful impact, shock
- Vascular disruption
- Heart attack, stroke, arteriovenous malformation (AVM), aneurysm, intracranial surgery
- Infectious disease, intracranial tumors, metabolic disorders
- Meningitis, certain venereal diseases, AIDS, insect-carried diseases, brain tumors, hypo/hyperglycemia, hepatic encephalopathy, uremic encephalopathy, seizure disorders
- Toxic exposure- poisonous chemicals and gases, such as carbon monoxide poisoning
Effects of an Acquired Brain Injury:
- An acquired brain injury commonly results in a change in neuronal activity, which affects the physical integrity, the metabolic activity or the functional ability of the cell.
- An acquired brain injury may result in mild, moderate or severe impairments in one or more areas, including cognition, speech-language communication, memory, attention and concentration, reasoning, abstract thinking, physical functions, psychosocial behavior, and information processing.
Adopted by the Brain Injury Association Board of Directors, March 14, 1997.
Symptoms of Acquired Brain Injury:
- Most symptoms of acquired brain injuries are very similar to that of traumatic brain injuries; however, there are some difficulties that are experienced more frequently or to a greater degree by persons with acquired brain injuries.
- This information is not intended to be a substitute for medical advice or examination. A person with a suspected brain injury should contact a physician immediately, go to the emergency room or call 911 in the case of an emergency.
- Symptoms can include thinking skills (especially memory), longer lengths of time spent in a vegetative state, severe behavioral problems (psychosis, depression, restlessness, combativeness, and hostility)
- Muscle movement disorders
Diffuse Axonal Injury
Neurons (nerve cells) have an extension to them called the axon. Axons allow for communication from one nerve cell to the other, through a chemical reaction. When there is motion in the brain, the axons can be pulled, stretched or torn, which results in cell death. When that occurs throughout the brain, it is called a diffuse axonal injury.
- Tearing of the axons cause brain chemicals to be released, causing additional injury.
- This kind of injury does not show up on a CT or MRI scan because the scan is not a microscope that can see these tiny cells.
- Diffuse axonal injury is often diagnosed on the basis of the person’s symptoms.
- Any time there is a loss of consciousness associated with a trauma event, there will be a diffuse axonal injury.
- A person with a diffuse axonal injury could present a variety of functional impairments depending on where the shearing (tears) occurred in the brain.
- A concussion can be caused by any significant blunt force trauma to the head such as a fall, car accident, or being struck on the head with an object.
- A concussion is the most common type of traumatic brain injury.
- A concussion can be caused by direct blows to the head, gunshot wounds, violent shaking of the head, or force from a whiplash type injury.
- Both closed and open head injuries can produce a concussion.
- The blood vessels in the brain may stretch and cranial nerves may be damaged.
- A person may or may not experience a brief loss of consciousness (not exceeding 20 minutes).
- A concussion may cause headache, nausea or vomiting, blurred vision, and loss of short-term memory.
- A concussion may or may not show up on a diagnostic imaging test, such as a CT Scan.
- Skull fracture, brain bleeding or swelling may or may not be present. Therefore, concussion is sometimes defined by exclusion and is considered a complex, neurobehavioral syndrome.
- A concussion can cause diffuse axonal type injury resulting in permanent or temporary damage.
- A blood clot in the brain can occur occasionally and be fatal.
- It may take a few months to a few years for a concussion to heal.
- A contusion is another name for a bruise or bleeding in the brain.
- It is caused when blood vessels are damaged or broken as a result of a direct impact.
- If the contusion is severe, it may require surgical removal.
- Coup-Contrecoup Injury describes contusions that are both at the site of the impact and on the complete opposite side of the brain.
- This injury occurs when the direct blow to the head is strong enough to harm the impacted side and cause it to “bump” the opposite side of the brain causing a contusion.
Second Impact Syndrome “Recurrent Traumatic Brain Injury”
- “Recurrent traumatic brain injury” can occur when a person suffers a traumatic brain injury before coming to a complete healing from the initial traumatic brain injury.
- There is no specific time frame between injuries, a loss of consciousness is not required and the second injury is more likely to cause brain swelling and widespread damage.
- Emergency medical treatments are required immediately because death can occur rapidly.
- Long-term effects of recurrent brain injury include, but are not limited to muscle spasms, increased muscle tone, rapidly changing emotions, hallucinations, and difficulty thinking and learning.
- Penetrating injury to the brain occurs when the direct blow to the head causes hair, bone or fragments from the penetrating object into the brain. It can occur from the impact of any sharp object such as a knife or bullet.
- The area of damage can be widened if the object travels through the skull at a low speed due to a ricochet within the skull.
- Another type of injury is labeled as a “through-and-through” injury, which occurs if the skull is penetrated by a sharp object that goes through the brain and exits the skull. These injuries will cause shearing, stretching and rupturing of brain tissue. (Brumback R. (1996). Oklahoma Notes: Neurology and Clinical Neuroscience. (2nd Ed.). New York: Springer.)
- The devastating traumatic brain injuries caused by bullet wounds result in a 91% firearm-related death rate overall. (Center for Disease Control. [Online August 22, 2002: http://www.cdc.gov/ncipc/didop/tbi.htm#rate]).
- Firearms are the single largest cause of death from traumatic brain injury. (Center for Disease Control. [Online August 22, 2002: http://www.cdc.gov/ncipc/didop/tbi.htm#rate]).
Shaken Baby Syndrome
- Shaken Baby Syndrome is also referred to as Abusive head trauma/inflicted traumatic brain injury or AHT. AHT can be caused by direct blows to the head, dropping or throwing a child or shaking a child, which causes the brain to be injured. Head trauma is the leading cause of death in child abuse cases in the United States.
- Blood vessels between the brain and skull rupture and bleed.
- The accumulation of blood causes the brain tissue to compress while the injury causes the brain to swell. This damages the brain cells.
- AHT can cause seizures, lifelong disability, coma, and in some cases, death.
- Irritability, changes in eating patterns, tiredness, difficulty breathing, dilated pupils, seizures, and vomiting are signs of Shaken Baby Syndrome. A baby experiencing such symptoms needs immediate emergency medical attention.
(The Shaken Baby Alliance. [Online August 22, 2002: www.shakenbaby.com])
- Locked-in Syndrome is a rare neurological condition in which a person cannot physically move any part of the body except the eyes.
- The person is conscious and able to think.
- Vertical eye movements and eye blinking can be used to communicate with others and operate environmental controls.
Anoxic Brain Injury
- Adequate oxygen is vital for the brain to function properly and when the brain does not receive enough or any oxygen, neurons begin to die and permanent anoxic brain injury can occur.
- Types of Anoxic Brain Injury:
- Anoxic Anoxia – Brain injury from no oxygen supplied to the brain.
- Anemic Anoxia – Brain injury from blood that does not carry enough oxygen.
- Toxic Anoxia – Brain injury from toxins or metabolites that block oxygen in the blood from being used.
Zasler, N. Brain Injury Source, Volume 3, Issue 3, Ask the Doctor
Hypoxic Brain Injury
- A Hypoxic Brain Injury results when the brain receives some, but not enough oxygen.
- Types of Hypoxic Brain Injury:
- Hypoxic Ischemic Brain Injury also called Stagnant Hypoxia or Ischemic Insult – Brain injury occurs because of a lack of blood flow to the brain due to a critical reduction in blood flow or blood pressure.